This provides that you're a) a nerd, b) comfortable voiding your warranty by rooting the phone and c) that your phone is even popular enough for there to be things like Cyanogenmod to install on it.
Sure, I did that with my HTC Incredible, but I shouldn't have had too and most people won't.
You don't need to be a nerd; you only need access to someone you trust who would do it for you. And plenty of folks wait until their warranty runs out before modifying the OS.
Sure, I did that with my HTC Incredible, but I shouldn't have had too and most people won't.